As an example of cutting inserts used for face milling cutters and end mills, for example, Japanese Unexamined Patent Publication No. 2010-523353 discloses a double-sided cutting insert including a major cutting edge 50 and a minor cutting edge 52.
However, when this cutting insert is attached to a holder, there is a risk that a region having a negative axial rake angle occurs in the vicinity of an upper end 58 of the major cutting edge 50, thus causing the problem that cutting resistance is increased in the region.
Hence there is a desire for a cutting insert that can further reduce the cutting resistance than conventional ones.